Acetabular prosthetic systems are well known in the field of orthopaedics. A prosthesis of this kind generally consists of a metal cup, or metal back, of substantially hemispherical shape, inside which is arranged an insert, for example made of polyethylene, in which is formed a cavity receiving a metal head. The whole assembly is intended to be received at the bottom of the patient's natural acetabulum.
To place the acetabular prosthesis at the bottom of the patient's acetabulum, and in particular to impact it at the bottom of the patient's acetabulum, there exist at present ancillary systems which screw into the bottom of the cup, the latter thus being pierced at its vertex. This is very detrimental with regard to wear once the cup is arranged in the acetabulum and therefore with regard to the life of this prosthesis. Another system consists in pressing on the inner wall of the cup. However, this solution does not work well, on account especially of a lack of adherence of the part of the gripping system which expands inside the cup to press against the inner wall of the cup at two diametrically opposed bearing points. This lack of adherence leads to untimely separation from the cup just when it is in fact desired to hold it for impaction.